To add a bit on PBS stations - PBS has a national contract that includes most cable providers:
https://www.ncta.com/news-and-events/media-room/article/1798
This contract was renewed this year:
http://www.pbs.org/about/blogs/news...-television-digital-cable-carriage-agreement/
Basically, each PBS station will get to choose four of their digital channels to be carried on cable systems, which can be x.1, x.2, x.3, and x.4 - or could be x.1, x.4, x.5, x.6 - any four of them that they want, so long as all programming carried is noncommercial in nature. Also, cable companies do not have to carry a public broadcasting channel when it duplicates one they already carry for more than 12 hours a day. (Example: If a market has two PBS stations and both stations carry the Create network 24x7 on a subchannel, only one of those must be carried on cable. But if one of them had Create for 12 hours a day and local programming for the other 12 hours (or any other non-duplicated programming) then both would be carried.
I wish we had a deal similar to this for all stations - however I would, for commercial stations, keep the nonduplication rule and add a rule limiting commercial time and paid programming hours so that any channels carried on cable would need to have actual programming not just shopping. I think it would be reasonable to limit program-length commercials to airing between 12 midnight and 6 am on such channels, and limit the amount of commercial breaks to an average of those on the main channel. (So if your x.1 has 20 minutes of commercials per hour, so could all your subchannels.)